Babka

Make the dough: Coat a large bowl with oil and set aside. Combine the milk, yeast, the 1 tablespoon sugar, and 1 cup flour in a small bowl and set aside. In the bowl of a standing mixer fitted with a dough hook, combine the remaining 6 cups flour, remaining sugar, salt, lemon zest, and raisins. With the mixer on low speed, add vanilla, egg yolks, 2 eggs, and the yeast mixture. Mix on low speed until a smooth, elastic dough forms -- about 10 minutes. Add the 1/2 cup butter and mix for 5 more minutes. Transfer the dough to the prepared bowl, turning to coat all sides with oil. Cover the bowl with a clean, damp kitchen towel and set dough aside to rise in a warm, draft-free place until it doubles in volume -- about 1 hour.

Shape the loaf: Coat two 8-inch round by 4-inch-deep baking dishes with remaining butter and lightly dust with the 2 tablespoons flour, shaking out any excess. Set aside. Punch down the dough, transfer it to a lightly floured surface, and divide it in half. Shape each half into a ball and place them in the prepared dishes. Cover with a clean, damp kitchen towel and let rise in a warm place until dough doubles in volume -- about 1 hour. Preheat oven to 350°F.

Bake the bread: Beat the remaining egg and lightly brush the top of babkas. Bake in the lower third of the oven for 15 minutes. Reduce the oven temperature to 300°F and continue to bake until the loaves are golden and sound hollow when tapped -- about 40 more minutes. Transfer the finished loaves to a wire rack to cool.